1. Field of the Invention
The present invention relates to a communication apparatus that communicates with an external apparatus, a control method therefor, and a computer-readable recording medium storing.
2. Description of the Related Art
Recently, a communication system which complies with a high definition multimedia interface (HDMI®) standard (hereinafter simply referred to as an “HDMI system”) has been proposed. An HDMI system includes a source apparatus, a sink apparatus, and a repeater apparatus. A source apparatus transmits video data and audio data. A sink apparatus includes a display unit that displays video data transmitted from the source apparatus. A repeater apparatus transmits video data and audio data received from the source apparatus to the sink apparatus.
In an HDMI system in which a source apparatus is connected to a repeater apparatus, when the repeater apparatus is powered on, the source apparatus acquires extended display identification data (EDID), which is recorded on the repeater apparatus, from the repeater apparatus. In addition, in order to transmit video data and audio data that conform to the specification of the repeater apparatus to the repeater apparatus, the source apparatus changes a setting of the video data and the audio data according to the information included in the EDID acquired from the repeater apparatus.
Japanese Patent Application Laid-Open No. 2006-203725 discusses an HDMI system in which a source apparatus compares manufacturer information included in an EDID acquired from a repeater apparatus and manufacturer information which is already recorded on the source apparatus and changes a setting of data based on a result of the comparison.
If the manufacturer information included in the EDID recorded on the source apparatus matches the manufacturer information included in the EDID acquired from the repeater apparatus, then the above-described conventional source apparatus determines that the same information is included in the EDID and does not change the setting of the data.
On the other hand, another repeater apparatus transmits an EDID of the repeater apparatus itself to the source apparatus as it is according to a status of connection between the repeater apparatus and an external apparatus. In addition, yet another repeater apparatus combines an EDID acquired from an external apparatus with an EDID of the repeater apparatus itself and transmits the updated (combined) EDID that includes capabilities of the external apparatus to the source apparatus.
Accordingly, on the source apparatus, even if the manufacturer information included in the EDID acquired from the repeater apparatus and the manufacturer information included in the already recorded EDID match each other, the information included in the acquired EDID and the information included in the recorded EDID may be different from each other.
In this case, the source apparatus may transmit the video data and audio data whose setting has been set according to the information included in the recorded EDID to the repeater apparatus without changing the setting of the data according to the information included in the acquired EDID. Accordingly, in this case, the repeater apparatus which can update the EDID may not receive video data and audio data that conform to the specification of the repeater apparatus.